Help with GraphEdit (to resolve stutter problems)

[tjb]

I am trying to resolve some video playback issues, and have downloaded a copy of graphedit. I'm hoping to be able to use this to determine where my problem lies.

In graphedit, if I select one of my Gbpvr recordings to render, I can create a graph that uses, for example, the ATI Mpeg decoder. When I play the recording in graphedit, everything is fantastic - no stutter, great picture, etc. However, if I specify the same ATI Mpeg decoder as the video decoder in config.exe, when I play the file in Gbpvr I get skipped frames etc. So there must be something else getting in the way.

Can someone tell me if there is a way to have graphedit display a graph for a recording that is currently running in Gbpvr? There is an option in graphedit to "Connect to a running graph in another application, but when I select this the list box is empty.

I feel like I'm getting very close to resolving the stutter that has plagued my system from day one, but just need a little guidance in how to get Gbpvr to use the same graph that I create in graphedit.

[sub]

If you create an HKEY_LOCAL_MACHINE\Software\Devnz\AddGraphToROT=1 (DWORD) registry setting, then you'll be able to remotely connect to the graph. The difference is most likely the video renderer.

Its recommended that you remove this registry setting after testing it though, since it can cause problems if left in place.

[tjb]

If you create an HKEY_LOCAL_MACHINE\Software\Devnz\AddGraphToROT=1 (DWORD) registry setting, then you'll be able to remotely connect to the graph. The difference is most likely the video renderer.

Its recommended that you remove this registry setting after testing it though, since it can cause problems if left in place.

Thanks, I can now connect to the graph. It looks very similar to the default graph created when I open a recording directly in graphedit. At first glance, the video renderers look the same (they are both called Video Renderer). However there is one difference. The one opened from a recording allows me to display the filter properties of the renderer. The one opened with GbPvr does not - it displays an error stating that "The requested Property Page could not be displayed".

I'm actually kind of confused - I'm running GbPvr in Vmr9 Custom mode, but the renderer is simply called "Video Renderer". If I look in the list of DirectShow Filters, there is one called "Video Mixing Renderer 9".

You mentioned that the problem is probably with my renderer. However, I have tried all renderer modes and still cannot get the smooth display that I get from graphedit. Any other suggestions?

[sub]

If you use either EVR or Overlay in GB-PVR then you should get identical results to GraphEdit with the EVR or Overlay renderers. You cant emulate exactly the same thing as VMR9 Custom in GraphEdit, but its effectively the same as "Video Mixing Renderer 9", but tells it to use your video cards Direct3D capabilities for drawing each frame.

Some decoders store settings on a per-application basis, which can cause them to behave slightly differently in different apps. I'm not sure whether the ATI decoder does this or not.

[tjb]

The default renderer in graphedit (when opening a recording) is "video Renderer", which I assume you are saying is Overlay mode. However, I can change the graph to use Video Mixing Renderer 9 and still get smooth display in graphedit, while Vmr9 Custom in GbPvr skips frames. Does this make sense?

Edit: I spoke too soon. I switched GbPvr to Overlay mode and connected with graphedit - it was using the "Video Mixing Renderer 9". I'm thinking I should give up and use a PCH to connect to my TV.

[sub]

Sorry, I dont know then. Maybe what I said about per-app decoders settings I mentioned above. Either way, GB-PVR isnt doing the playing itself - it just hooks up these decoders and renderers and tell it what window to draw the video to and directshow takes care of the rest.

[tjb]

After playing with this for many days, it appears that Gbpvr does indeed usa a slightly different VMR9 renderer than Windows Media Player. If I look at the properties of the Purevideo decoder in both cases, WMP says it is using the "Video Mixing" renderer and Gbpvr says "Video Mixing (DirectX 9)". But they both show they are using hardware acceleration DirectX VA Mode C (idct).

I don't guess there is any way to force Gbpvr to use the same renderer as WMP is using? This is the only difference in the setup of the two apps, and WMP in VMR mode works flawlessly. I have tried three different graphics cards (nVidia 6600, ATI 3450, and nVidia 9500GT) and they all exhibit the same problems.

[sub]

It uses the same VMR9 renderer as everything else in the system, but it does use the custom allocator/renderer option to force the renderer to use Direct3D rather than DirectDraw for displaying each frame on the screen. You cant emulate this in GraphEdit. If this isnt working well enough for you, other than trying other decoders, pretty much all you can do is switch to EVR or Overlay.

[tjb]

OK. Thanks for the help - just trying to understand this a little better.